SODIUM CARBOXY METHYL CELLULOSE CAS#9004-32-4

Products Description of Sodium Carboxymethyl Cellulose (CMC) CAS#9004-32-4

Sodium carboxymethyl cellulose (CMC), also called cellulose gum, is a carboxymethylated derivative of natural cellulose and the primary anionic cellulose ether. It is typically produced by reacting cellulose with caustic soda and monochloroacetic acid, forming an anionic polymer with a molecular weight ranging from several thousand to millions.

CMC appears as a white or milky-white fibrous powder or granule with a density of 0.5–0.7 g/cm³. It is nearly odorless, tasteless, and hygroscopic. The powder disperses easily in water to form a transparent colloidal solution, while remaining insoluble in organic solvents such as ethanol. A 1% aqueous solution has a pH of 6.5–8.5, and its performance is optimal at neutral pH. Viscosity decreases significantly at pH values below 5 or above 10.

CMC exhibits good thermal stability: viscosity increases rapidly below 20°C, changes slowly around 45°C, but prolonged heating above 80°C can denature the colloid and reduce performance. It is highly stable in alkaline solutions but hydrolyzes easily in acidic conditions, with precipitation occurring at pH 2–3 or in the presence of multivalent metal salts. Solid CMC is stable under light and room temperature and can be stored long-term in a dry environment.